出于某种原因，我的Django web应用程序中的MySQL表使用不同的格式，这会导致外键约束错误（如this question）。
下面是表格格式的样子。
SHOW TABLE STATUS WHERE `Name` in ('') ...
+----------------------------+--------+---------+------------+--------+----------------+-------------+------------------+--------------+-----------+----------------+---------------------+---------------------+---------------------
| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time
+----------------------------+--------+---------+------------+--------+----------------+-------------+------------------+--------------+-----------+----------------+---------------------+---------------------+---------------------
| table_0 | MyISAM | 10 | Dynamic | 341 | 83 | 28472 | 281474976710655 | 19456 | 0 | 346 | 2013-09-05 15:52:11 | 2014-01-10 14:17:18 | 2013-09-05 15:52:11
| table_1 | MyISAM | 10 | Dynamic | 66422 | 49 | 3297260 | 281474976710655 | 2025472 | 0 | 141146 | 2013-07-20 19:12:24 | 2014-01-10 19:20:21 | 2013-07-20 19:12:27
| table_2 | MyISAM | 10 | Dynamic | 3 | 53 | 160 | 281474976710655 | 3072 | 0 | 4 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27
| table_3 | MyISAM | 10 | Dynamic | 8 | 99 | 796 | 281474976710655 | 3072 | 0 | 10 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27
| table_4 | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 1024 | 0 | 1 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27 | 2013-07-20 19:12:27
| table_5 | InnoDB | 10 | Compact | 0 | 0 | 16384 | 0 | 16384 | 7340032 | 1 | 2013-11-20 14:04:02 | NULL | NULL
| table_6 | InnoDB | 10 | Compact | 0 | 0 | 16384 | 0 | 16384 | 7340032 | 1 | 2013-11-20 14:03:39 | NULL | NULL
| table_7 | MyISAM | 10 | Dynamic | 860 | 125 | 107624 | 281474976710655 | 25600 | 0 | 977 | 2013-11-20 14:04:35 | 2014-01-06 18:32:57 | 2013-11-20 14:04:35
| table_8 | MyISAM | 10 | Fixed | 6632 | 21 | 139272 | 5910974510923775 | 173056 | 0 | 6753 | 2013-07-20 19:16:47 | 2014-01-09 11:26:36 | 2013-07-20 19:16:47
我试图更新this question中描述的表格格式。但收到以下错误。
mysql> SET FOREIGN_KEY_CHECKS=0;
mysql> alter table ztrap_emailreportoptin engine = MyISAM;
ERROR 1217 (23000): Cannot delete or update a parent row: a foreign key constraint fails
我怎样才能使发动机在两个表之间保持一致？
（还有，你知道这是怎么开始的吗？）
最佳答案
MyISAM does not support foreign keys。
若要转换为MyISAM，需要先删除所有外键约束。
错误消息告诉您表ztrap_emailreportoptin引用了另一个表，或者被另一个表引用。
您可以列出此类参考：
SELECT
table_name, column_name, constraint_name,
referenced_table_name, referenced_column_name
FROM information_schema.key_column_usage
WHERE referenced_table_name IS NOT NULL;
但是，我建议将表转换成InnoDB。
关于python - 将表从InnoDB转换为MyISAM时，“外键约束失败”，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/21055466/